Beneficial Eye Bacteria Helps Prevent Infection
By LabMedica International staff writers Posted on 26 Jul 2017 |
Image: C. mastitidis is a commensal bacterium living on the surface of the eye (Photo courtesy of Dr. Rachel Caspi and Dr. Anthony St. Leger, National Eye Institute).
A team of microbiologists identified Corynebacterium mastitidis as a commensal bacterium living in the conjunctiva of the eye where it induces the production of interleukin (IL)-17, a signaling protein critical for host defense.
Mucosal sites such as the intestine, oral cavity, nasopharynx, and vagina all have associated commensal flora. The surface of the eye is also a mucosal site, but proof of a living, resident ocular microbiome had not been established previously.
Investigators at the [U.S.] National Eye Institute (Bethesda, MD, USA) used a mouse model of ocular surface disease to reveal that commensals were present in the mucosa of the eye and had functional immunological consequences.
The investigators reported in the July 11, 2017, online edition of the journal Immunity that they had isolated one such candidate commensal, Corynebacterium mastitidis, and showed that this organism elicited a commensal-specific interleukin-17 response from gamma delta T-cells in the ocular mucosa that was central to local immunity. The commensal-specific response drove neutrophil recruitment and the release of antimicrobials into the tears and protected the eye from infection by pathogenic Candida albicans or Pseudomonas aeruginosa.
These findings provided direct evidence that a resident commensal microbiome existed on the ocular surface and identified the cellular mechanisms underlying its effects on ocular immune homeostasis and host defense.
"This is the first evidence that a bacterium lives on the ocular surface long-term," said senior author Dr. Rachel Caspi, a senior researcher at the [U.S.] National Eye Institute. "This work addresses a longstanding question about whether there is a resident ocular microbiome. We still do not know what enables C. mastitidis to successfully establish itself in the eye, whereas other similar bacteria fail to colonize."
Related Links:
National Eye Institute
Mucosal sites such as the intestine, oral cavity, nasopharynx, and vagina all have associated commensal flora. The surface of the eye is also a mucosal site, but proof of a living, resident ocular microbiome had not been established previously.
Investigators at the [U.S.] National Eye Institute (Bethesda, MD, USA) used a mouse model of ocular surface disease to reveal that commensals were present in the mucosa of the eye and had functional immunological consequences.
The investigators reported in the July 11, 2017, online edition of the journal Immunity that they had isolated one such candidate commensal, Corynebacterium mastitidis, and showed that this organism elicited a commensal-specific interleukin-17 response from gamma delta T-cells in the ocular mucosa that was central to local immunity. The commensal-specific response drove neutrophil recruitment and the release of antimicrobials into the tears and protected the eye from infection by pathogenic Candida albicans or Pseudomonas aeruginosa.
These findings provided direct evidence that a resident commensal microbiome existed on the ocular surface and identified the cellular mechanisms underlying its effects on ocular immune homeostasis and host defense.
"This is the first evidence that a bacterium lives on the ocular surface long-term," said senior author Dr. Rachel Caspi, a senior researcher at the [U.S.] National Eye Institute. "This work addresses a longstanding question about whether there is a resident ocular microbiome. We still do not know what enables C. mastitidis to successfully establish itself in the eye, whereas other similar bacteria fail to colonize."
Related Links:
National Eye Institute
Latest BioResearch News
- Genome Analysis Predicts Likelihood of Neurodisability in Oxygen-Deprived Newborns
- Gene Panel Predicts Disease Progession for Patients with B-cell Lymphoma
- New Method Simplifies Preparation of Tumor Genomic DNA Libraries
- New Tool Developed for Diagnosis of Chronic HBV Infection
- Panel of Genetic Loci Accurately Predicts Risk of Developing Gout
- Disrupted TGFB Signaling Linked to Increased Cancer-Related Bacteria
- Gene Fusion Protein Proposed as Prostate Cancer Biomarker
- NIV Test to Diagnose and Monitor Vascular Complications in Diabetes
- Semen Exosome MicroRNA Proves Biomarker for Prostate Cancer
- Genetic Loci Link Plasma Lipid Levels to CVD Risk
- Newly Identified Gene Network Aids in Early Diagnosis of Autism Spectrum Disorder
- Link Confirmed between Living in Poverty and Developing Diseases
- Genomic Study Identifies Kidney Disease Loci in Type I Diabetes Patients
- Liquid Biopsy More Effective for Analyzing Tumor Drug Resistance Mutations
- New Liquid Biopsy Assay Reveals Host-Pathogen Interactions
- Method Developed for Enriching Trophoblast Population in Samples